Coloration of polyolefins



United States Patent ABSTRACT OF THE DISCLOSURE A process for improvingthe dye-receptivity of articles containing or consisting ofstereoregular polyolefins characterized by formation within the articleof a quaternized amine from an amine and a quaternizing agent ,which areseparately introduced into the article and interact only with thearticle. Preferred quaternizing agents are esters of oxyacids ofphosphorus and sulfur a This is a continuation-in-part of priorcopending United States applications Ser. No. 120,948 filed June 30,1961, and Ser. No. 124,325 filed July 17, 1961, both now abandoned.

v This invention relates to the coloration of polyolefins and inparticular provides a process whereby the dyeaflinity of articlescomposed of stereoregular polyolefins I may be improved.

Stereoregular polyolefins are polyolefins having a high degree ofmolecular symmetry. These polymers, notably isotactic and syndiotacticpolypropylene, are nOW well known as a source of valuable shapedarticles such as filamerits, fibers and films. The hydrocarbon polymersare, however, hydrophobic in character and contain no groups which arechemically reactive toward dyestuffs. The coloration of articlescomposed of stereoregular polyolefins therefore presents a considerableproblem since the application of dyestuffs by conventional methods isineffective. It is important that this difficulty be overcome tofacilitate the development and use of isotactic polyalphaolefins intextiles.

According to our invention we provide a process for improving thedye-receptivity of articles containing or consisting of stereoregularpolyolefins characterized by formation within the article of aquaternized amine from an amine and a quaternizing agent which areseparately introduced into the article and interact only with thearticle.

In one embodiment, the process comprises the inclusion in the article ofan amine, either by assimilation or by the addition of the amine to thepolymer composition from which the article is formed, and subsequenttreatment of the article with a quaternizing agent.

By quaternizing agent is meant a reagent, conveniently in liquid form,which converts the amine to a quaternary ammonium salt, for example (RN)+X- where R is an organic radical and X is the salt-forming anion. Theliquid reagent is preferably the undiluted quaternizing substance butmay be a solution of this substance in an inert solvent. When the amineis added to the polymer composition prior to fabrication of the article,it is advantageous that'the boiling point should be high-in order tominimize loss by volatilization, for example, during melt extrusion. Itis further advantageous to use an amine which is compatible with thepolyolefin, and we have. found tertiary amines containinglonghydrocarbon chains 6C) to be .very suitable. The amine may also bein the.

3,337,932 Patented Aug. 13, 1968 form of a polymeric substance such as'apo1y(dialkylaminoalkylene acrylate) While the covalent nature of aminesand of quaternizing agents enables these substances to penetrate intopolyolefins, the ionic quaternary salts formed become trapped in thestructure and provide centers of afiinity for many classes of dyestuffsbut particularly for the important class of acid wool dyestuffs. Aciddyestuffs may be applied to articles of stereoregular polyolefins whichhave undergone the treatment of our invention by conventional methodsincluding the use of carriers. Wash fastness of the colors has been verysatisfactory.

In general, in this embodiment it has been found that between 1 and 10percent by weight of quaternary ammonium salt is adequate to impart gooddye aifinity to articles.

This embodiment of the process has been applied most successfully tofilaments and fibers of stereoregular polymers and copolymers ofpropylene, and it is possible to introduce and quaternize the amine atany stage in the course of spinning and drawing and to operate, ifdesired, in continuous fashion. It has, however, been observed thatafter drawing the movement of amine either into or out of the polyolefinis restricted and it is accordingly desirable to introduce the aminebefore drawing, i.e., before a high degree of molecular orientation hasbeen created in the polymer.

Stereoregular polypropylene dyed in accordance with this embodiment maybe used in the form of staple fiber in the following articles whereinimproved dyeability is important:

Carpets Blankets Woolen garments such as dresses, coats and suits Furfabrics Velvets Furnishing fabrics such as pile fabrics for upholsteryand repps for curtains Knitted articles such as jersey fabrics andunderwear Non-woven fabrics such as linings and interlinings In the formof bulked filament yarn stereoregular polypropylene of improveddyeability is particularly useful in carpets and other floor coverings.

Improved dye-affinity thus achieved may also be useful in bulked yarnobtained by mixing staple fiber of stereoregular polypropylene withanother staple fiber (such as cotton or viscose), e.g., before or aftercarding, and subsequently heating the blend under little or no tension.The bulking effect results from the high degree of shrinkage whichoccurs in the polypropylene fibers. The high shrinkage may be similarlyutilized in the production of seersucker fabrics wherein polypropyleneyarns are first combined with yarns composed of other materials.

According to another embodiment of the invention, we provide a processfor the production of articles of polyolefins having improveddye-affinity characterized in that the article is formed from astereoregular polyolefin to which an ester of an oxyacid of phosphorusor sulfur has been added and is subsequently treated with an amine whichis assimilated and reacts with the ester of the oxyacid to form aquaternary ammonium salt. Both the ester of the oxyacid of phosphorus orsulfur and the amine should preferably be compatible with the polyolefinand for this purpose a low degree of polarity is advantageous. It isalso desirable that the compound of phosphorus or sulfur should' be highboiling and stable at the high temperatures commonly associated withmelt extrusion processes. To meet the criteria of miscibility, stabilityand volatility, .we have foundsubstances of a fatty or aromaticcharacter, for example, where the phosphorus, sulfur J or amine groupsare attached to a long hydrocarbon chain 6C) or to a high molecularweight aromatic unit, to be very useful.

Among esters of oxyacids of phosphorus and sulfur which have been usedin this embodiment of the process of our invention are compounds whereinat least one of the ester-forming groups is labile in character, e.g.,benzyl, methyl and lower alkyl groups. Compounds of this type includephosphates having general formula (ROhF-OMe phosphonates R. i 0Mephosphinates P-OMe sulphonates R-SO Me and sulphates ROSO Me Where R andR are alkyl or aryl groups which may themselves contain substituents.The introduction of fatty substances is typified by our use of methylesters of methylene dinaphthalene disulphonic acid and cetyl hydrogensulfate.

In the amine after-treatment tertiary amines including trioctylamine,trinonylamine, tridecylamine and cetyldimethylamine have beensuccessfully applied and their interaction with the ester of phosphorusor sulfur may be illustrated as follows:

0 (RO) i OMe RQIN 0 II (RO)2PO-.R3NMe Quaternary salt of P acid Thisform of the process has been applied most successfully to filaments andfibers of stereoregular polymers and copolymers of propylene. In thisembodiment up to about 10 percent by weight of the phosphorus or sulfurcompound is added to the polyolefin which is then spun at temperaturesup to 150 C. above the melting point. The amine treatment may beintegrated with subsequent drawing or stretching by passing thefilaments through a bath containing the amine immediately before thisstep. In this Way, penetration of the amine into the polymer is assistedby contact before orientation has taken place and by the passage of theyarn over a heated roll, pin or plate or through a hot tube as inconventional drawing techniques. The quaternization reaction may beaccelerated by further heat treatment of yarns or the yarns may be keptat ordinary temperatures for the requisite period before excess amine isremoved by washing.

Articles produced in accordance with this embodiment of the inventionhave affinity for many classes of dyestuffs but the improvement is mostmarked toward disperse and acid wool dyestuffs which may be successivelyapplied by conventional methods. In general, the presence of between 2and 5 percent by weight of ester or phosphorus or sulfur in the originalpolymer composition in conjunction with treatment with excess amine willadequately enhance the dye-receptivity of shaped articles for mostpurposes.

Stereoregular polypropylene dyed in this embodiment may be used in theform of staple fiber in the following articles wherein improveddyeability is important:

Carpets Blankets Woolen garments such as dresses, coats and suits Furfabrics Velvets Furnishing fabrics such as pile fabrics for upholsteryand repps for curtains Knitted articles such as jersey fabrics andunderwear Non-woven fabrics such as linings and interlinings In the formof bulked filament yarn stereoregular polypropylene of improveddyeability is particularly useful in carpets and other floor coverings.

Polypropylene fiber may be used in the form of blends with other fibers,notably wool, cotton, silk and synthetic fibers such as polyesters andpolyamides and acrylic polymers.

Improved dye-afiinity achieved in this embodiment may also be useful inbulked yarn obtained by mixing staple fiber of stereoregularpolypropylene with another staple fiber (such as cotton or viscose),e.g., before or after carding, and subsequently heating the blend underlittle or no tensionff he bulking effect results from the high degree ofshrinkage which occurs in the polypropylene fibers. The high shrinkagemay be similarly utilized in the production of Seersucker fabricswherein polypropylene yarns are first combined with yarns composed ofother materials.

In outlets where good light fastness is necessary, it is advantageous toincorporate a stabilizer, such as a known UV. absorber or oxygenacceptor, in polyolefin articles modified by our process, and this maybe done at any stage in the manufacture of the article or the polyolefinof which it is composed.

The following examples in which all parts and percentages are by weightare provided only for the purpose of illustrating our invention.Examples 1-5 illustrate the first embodiment described above andExamples 6-10 illustrate the second embodiment.

Example 1 Isotactic polypropylene powder (9 parts) was intimately mixedwith tri-n-octylamine (1 part). The mixture was melt spun at 260 C. Theresultant fiber was immersed in a bath of dimethyl sulphate at 20 C. for30 minutes. -It was then washed with concentrated ammonia solution,followed by water. The treated fiber showed a strong afiinity for aciddyestuffs, e.g., Carbolan Blue B (Color Index Acid Blue 138) and A20Geranine 2G (C.I. 18050).

Example 2 Isotactic polypropylene fiber was immersed and drawn in cetyldimethylamine at C. before treatment with dimethyl sulphate at 20 C. for30 minutes. The fiber, after washing with ammonia solution and Water,showed similar aflinity for acid dyestuffs to that obtained in Example1.

Example 3 To isotactic polypropylene powder there was added 5% of poly(diethylaminoethyl methacrylate) and the composition was melt spun at240 C. The fibers were immersed in dimethyl sulphate at 80 C. for 5minutes and subsequently washed with ammonia and water before drawing.Good affinity was present toward disperse and acid dyestuffs such asDispersol Fast Scarlet G (C.I. 11-110) and Carbolan Yellow 36 (Cl. AcidYellow 72).

Example 4 Isotactic polyproplyene filaments were immersed intrinonylamine at room temperature and subsequently drawn at C. at drawratio 5/1. The drawn yarn, containing about 1% of amine, was nowimmersed in dimethyl sulphate for twenty minutes, then washed withammonia and water. The treated fibers showed a strong affinity for aciddyestuffs, e.g., Azogeranine 2G (C.I. 18050), Coomassie Fast Black BS(C.I. 26370), Coomassie Green 3G (C.I. 65005) and Coomassie Navy Blue2RN (C.I. 26360).

Example 5 A sample of linear polyethylene (Marlex) film was subjected tothe procedure of Example 2 and showed substantial improvement indye-aflinity.

Similar results were achieved under conditions of Examples 1-4 whenmethyl iodide, formic acid/formaldehyde and tetramethylene dibromidewere used as quaternizing agents in place of dimethyl sulphate.

Similar results were also obtained under the conditions of Examples 1-4using a /80 (mol.) ethylene/propylene copolymer and fibers thereof inplace of isotactic propylene polymer and fiber.

By comparison untreated fibers of polypropylene had little affinity fordisperse dyestuffs and no alfinity for acid dyestuffs and, while fiberscontaining unquaternized amine had appreciable dye-affinity, the colorswere less intense and of inferior wash fastness particularly in undrawnyarn.

Examples 6-10 Isotactic polypropylene was intimately mixed with estersof oxyacids of phosphorus or sulfur in the quantities shown and themixtures melt spun. The filaments were then moistened with amines anddrawn over a heated pin using a draw ratio of about 3.5/1. After keepingfor fifteen hours at ordinary temperatures of for two hours at 100 C.,the filaments were chopped up and the fibers dyed in conventional mannerwith dyestuffs as shown in the table below.

ments, fibers and films of stereoregular homopolymers and copolymers ofpropylene.

3. A process according to claim 1 wherein the amine is a tertiary aminecontaining at least one hydrocarbon chain having more than six carbonatoms.

4. A process according to claim 1 wherein said ester is added to thestereoregular polyolefin in amount up to ten percent by weight and thearticle formed from the composition is treated with excess of an amine.

5. A process according to claim 4 in which said ester is added in anamount of two to five percent by weight.

6. A process according to claim 1 wherein filaments are spun from acomposition comprising stereoregular polypropylene containing said esterin an amount up to ten percent by weight at temperatures up to 150 C.above the melting point and are treated with an amine prior to drawingand stretching.

7. A process according to claim 6 wherein the stereoregularpolypropylene is isotactic polypropylene.

8. A process for the production of shaped polyolefin articles as setforth in claim 1 in which said ester is methyl bis(p-methoxy-carbonylphenyl) phosphate.

9. A process for the production of shaped polyolefin articles as setforth in claim 1 in which said ester is methyl toluene-p-sulphonate.

10. A process for the production of shaped polyolefin articles as setforth in claim 1 in which said ester is dimethyl naphthalene-1,S-disulphonate.

11. A process for the production of shaped polyolefin Spinning FiberProperties N 0. Additive (Ester of P or S acid) Amount, Temp. Amineafter Treatment percent C) Dyestufi and Color Index Shade Reference 6Methyl bis(p-methoxy-carbony1 5 260 Cetyl dirnethylamine... Azogeranine2G (C.I.18050) Deep red.

phenyl) phosphate. 7 Methyl toluene-p-sulphonate.... 2 210-220Tri-n-octylamine C(oglaSSle Green 3G (C.I. Very deep 5 05 green. 8Dimethyl naphtahlene 1, 5- 2 210-220 Trl-n-octylamine Carbolan Crimson3B (0.1. Deep crimson.

disulphonate. acid red 139).

Tridecylamine Cozijmlaszsfijgfilalavy Blue 2RN Very deep blue. Cetyldimethylamine- Azog er amne 2o 0.1. 1s0s0) Deep red. 9 Cetyl methylsulphate 2 210-220 Trinonylamine CarbglanuYell;2t;' 3G (Cl. Deep yellow.

aci ye ow 1O Methyl diphenyl phosphinate-.. 5 260 Cetyl dimethylamine-..Azogeranine 2G (Cl. 18050).-- Deep) red.

Dispersol Fast Scarlet (0.1. 11110).

Similar results were obtained under the conditions of articles as setforth in claim 1 in which said ester is cetyl Examples 6-10 when a 10/90(mol.) ethylene/propylene stereoregular copolymer was used in place ofisotactic polypropylene and when the compositions were extruded in theform of film instead of filament.

We claim:

1. A process for the production of shaped polyolefin articles which haveimproved dye affinity comprising forming the article from an intimatemixture of a stereoregular polyolefin and an ester selected from thegroup consisting of methyltoluene-p-sulphonate; dimethylnaphthalene-1,5- disulphonate; cetyl methyl sulphate; methyl diphenylphosphinate; and methyl bis(p-methoxycarbonyl phenyl) phosphate andsubsequently treating the article with an amine which reacts with theester to form a quaternary ammonium salt.

2. A process according to claim 1 wherein the polyolefin article is amember of the group consisting of filamethyl sulphate.

12. A process for the production of shaped polyolefin articles as setforth in claim 1 in which said ester is methyl diphenyl phosphinate. 0

References Cited NORMAN G. TORCHIN, Primary Examiner.

DONALD LEVY, Assistant Examiner.

